Dinosaurs were definitely killed by asteroid and not volcano, new study says
Dinosaurs were already struggling to survive prior to the asteroid
{{#rendered}} {{/rendered}}If there was any doubt that the dinosaurs went extinct due to the massive asteroid that hit Earth 65 million years ago, a new study hopes to put the controversy to bed.
The research notes that the asteroid impact is the sole reason that nearly 75 percent of all species on the planet were wiped out and not a volcanic explosion in the Deccan region, as has been previously suggested.
"We show that the asteroid caused an impact winter for decades, and that these environmental effects decimated suitable environments for dinosaurs," the study's lead author, Dr. Alessandro Chiarenza, from the Imperial College London, said in a statement. "In contrast, the effects of the intense volcanic eruptions were not strong enough to substantially disrupt global ecosystems.
{{#rendered}} {{/rendered}}Ankylosaurus magniventris drinking as the asteroid strikes. (Credit: Fabio Manucci)
MASSIVE ASTEROID EXPLOSION THAT KILLED THE DINOSAURS BENEFITED BACTERIA, STUDY SAYS
“Our study confirms, for the first time quantitatively, that the only plausible explanation for the extinction is the impact winter that eradicated dinosaur habitats worldwide," Chiarenza added.
In December 2019, a separate study was published by researchers that suggested dinosaurs were already struggling to survive prior to the asteroid due to a sharp increase in mercury levels caused by a massive volcano eruption of the Deccan Traps. These eruptions, which occurred 66 million years ago, are believed to have formed much of western India.
{{#rendered}} {{/rendered}}Chiarenza and the other researchers built models that looked at how different scenarios would affect the dinosaurs, including reductions in sunlight to varying degrees; the impact to the environment as a result of the asteroid impact, such as temperature and rainfall; and mapping where the conditions would still exist after an asteroid impact or volcanic eruption to come up with their findings.
SCIENTISTS UNCOVER NEW EVIDENCE OF THE ASTEROID THAT KILLED OFF THE DINOSAURS
“Instead of only using the geologic record to model the effect on climate that the asteroid or volcanism might have caused worldwide, we pushed this approach a step forward, adding an ecological dimension to the study to reveal how these climatic fluctuations severely affected ecosystems," University of Bristol professor and study co-author Dr. Alex Farnsworth added.
{{#rendered}} {{/rendered}}After the asteroid caused a "drastic global winter," any kind of volcanic eruption would have caused a restoration to many habitats, causing life to thrive again, the researchers noted.
“We provide new evidence to suggest that the volcanic eruptions happening around the same time might have reduced the effects on the environment caused by the impact, particularly in quickening the rise of temperatures after the impact winter," Chiarenza added. "This volcanic-induced warming helped boost the survival and recovery of the animals and plants that made through the extinction, with many groups expanding in its immediate aftermath, including birds and mammals.”
The research has been published in Proceedings of the National Academy of Sciences.
{{#rendered}} {{/rendered}}Experts continue to learn more about the time period surrounding the dinosaur extinction, including about the asteroid itself.
A separate study published in January also said that the reason the dinosaurs went extinct was "all about the asteroid," placing more doubt on any impact of a volcanic eruption impacting the climate.
{{#rendered}} {{/rendered}}The asteroid may have also acidified Earth's oceans after its impact, according to a study published in October 2019.
A separate study, published in January 2019, put forth a theory that the impact from the space rock also caused a worldwide tsunami that reached more than 5,000 feet in the air.
Another study published in September 2019 compared the impact of the asteroid to the power of 10 billion atomic bombs.
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